In the long episode, Galactica launches a suicide mission to rescue Hera from "the Colony", a Cylon base that is in a stable orbit within a black hole's accretion disk, while the rest of the fleet waits at a different point in space for their return. The issue here is, obviously, that a trip that close to a black hole will have a time dilation effect on the Galactica crew, slowing time considerably. Therefore, the fleet should have waited a lot longer than what is shown on the show.

It's weird that nobody has written about this online. I just wanted to mention it here as a reference for all those pedantic, plot-hole-seeking people out there. Also, as a question, has this point ever been officially discussed? I would love to see some excuse!

  • I suggest the best answer to this question would include the math to show how much actual time dilation there would be in the situation depicted. Despite some movies showing significant time dilation that relates to the plot, I’m not sure that planets, people, or space ships could always withstand the tidal forces that would exist in those scenarios. Perhaps it’s BSG that had the more accurate depiction overall. Someone would have to do the math to be sure. Commented Apr 3, 2023 at 2:37
  • arxiv.org/pdf/1601.02897v2.pdf
    – buræquete
    Commented Apr 3, 2023 at 8:40
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    “This place is not for discussing relativity” - I’m confused. Isn’t your question about relativity? Regarding my comment, of course there is significant time dilation if you are close enough to a black hole, what I’m wondering is first, how close is close enough and was the planet actually close enough (an accretion disk could be very large). Second, suppose the planet is close enough, then are there many other things that aren’t realistic, as in tidal forces and other effects that would destroy or seriously change the planet. Commented Apr 3, 2023 at 11:20

2 Answers 2


Short answer: There's probably no meaningful time dilation on The Colony.

An accretion disc can vary in size depending on a huge number of factors, but in general the disc is many dozens or even hundreds of times the radius of the event horizon.

Time dilation is infinite at the event horizon, but you have to be very close (within a few radii) to experience any meaningful dilation. The formula is sqrt(1-(1/r)) where r is your orbital distance measured in event-horizon-radii. So if you're orbiting 30 times further away than the radius of the event horizon itself (say, if the event horizon has a radius of 5 km, you're 150 km away), then you'd be at a dilation factor of 0.983, which is effectively normal time. Your clocks would be off by just about 1 minute per hour spent at that distance. (It's actually a little more complicated than that because that's only the dilation due to gravity, and there's also velocity and frame dragging involved, but this should be good enough for a TV show.)

Given the Colony is far enough away that tidal force wasn't ripping it apart, it shouldn't be experiencing enough time dilation to make things really weird by comparison to "flat" space, at least in human-time.


Yeah, it has been discussed among the viewers. But to my knowledge, there has never been an official explaination.

We have seen from movies such as Interstellar, when a person gets closer to an object with massive gravitational pull, this person will experience gravitational time dilation, e.g. time goes slower.

But in this TV show, its creators chose to ignore this fact in the interest of easier story-telling, IMO.

Not all science fictions are accurate due to various reasons.

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    I don’t think we can take for granted that Interstellar is more accurate. For example, the massive tidal forces depicted in Interstellar possibly would lead to the removal of the atmosphere and surface water from the planet. Also such tidal forces usually create significant tectonic activity (as in the moons of Jupiter, like Io) and there was no tectonic activity depicted in Interstellar. Commented Apr 3, 2023 at 2:40
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    Agree with @ToddWilcox. Interstellar may have been inspired by actual physics, but I wouldn't say it modelled the physical reality particularly accurately. Commented Apr 3, 2023 at 17:33

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